[angelf0926]

Hey guys I need some help...someone just offered me these pair of heads yes. casting 3964290 for $100..if I end up buying these heads I am definitely going to get them cleaned up..I did some research and found out these heads are from the early 70's, closed chambers on the ls-5 engines...I have a gen v with the peanut ports..I decided that I want to reach 500hp..I have the peanut ports and heard the power on these heads are restricted to 400-450 hp...would these heads fit my block? If so, would you recommend these heads?? Any input is.very much appreciated

[F-BIRD'88]

There is a special head gasket that allows using the old gen IV "Mark IV" cylinder heads on a Gen V block. I do not know the part number.

The issue is coolant hole mismatch.

[angelf0926]

Oh okay...what are the pros and cons of the mark iv?? And will I be having issues with the heads being closed chamber?

[V305]

Originally Posted by F-BIRD'88

There is a special head gasket that allows using the old gen IV "Mark IV" cylinder heads on a Gen V block. I do not know the part number.

The issue is coolant hole mismatch.

I believe it was Victor Reinz Brand, I think I saw a carcraft article using those gaskets

[DoubleVision]

Mark IV heads on Gen V 454 block

[angelf0926]

Yeah Ive heard about the victor reinz gaskets as well as the fel pro gaskets..if I were to purchase these gaskets...would it seal the heads for good without any leaks? Or would I have to make a few mods? I've been doing a ton of research regarding this topic but I still haven't gotten a straight up answer whether or not its a good idea..some say yes they've been successful and others say that its a bad idea..any engine expert out there can you share with us your knowledge on this topic? Is it a good idea to put these heads on a gen v or am I asking for serious problems? Thx for your input